// Copyright (c) 2006-2008 Max-Planck-Institute Saarbruecken (Germany).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org)
//
// $URL: https://github.com/CGAL/cgal/blob/v6.1/Number_types/include/CGAL/Sqrt_extension/Modular_traits.h $
// $Id: include/CGAL/Sqrt_extension/Modular_traits.h b26b07a1242 $
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s)     : Michael Hemmer   <hemmer@mpi-inf.mpg.de>


#ifndef CGAL_SQRT_EXTENSION_MODULAR_TRAITS_H
#define CGAL_SQRT_EXTENSION_MODULAR_TRAITS_H

#include <CGAL/basic.h>
#include <CGAL/Residue.h>
#include <CGAL/Modular_traits.h>

namespace CGAL {

/////////// MODULAR_TRAITS BEGIN

template< class COEFF, class ROOT, class ACDE_TAG, class FP_TAG>
class Modular_traits< Sqrt_extension<COEFF,ROOT,ACDE_TAG,FP_TAG> > {

private:
  typedef Sqrt_extension<COEFF,ROOT,ACDE_TAG,FP_TAG> EXT;
    typedef Modular_traits<COEFF> MT_COEFF;
    typedef Modular_traits<ROOT>  MT_ROOT;
    typedef typename MT_COEFF::Residue_type Residue_type_coeff;
    typedef typename MT_ROOT::Residue_type  Residue_type_root;
public:
    typedef EXT NT;
    typedef typename MT_COEFF::Is_modularizable Is_modularizable;
    typedef Sqrt_extension<Residue_type_coeff, Residue_type_root, ACDE_TAG,FP_TAG> Residue_type;

    struct Modular_image{
        Residue_type operator()(const EXT& a){
            typename MT_ROOT::Modular_image mod_image_root;
            typename MT_COEFF::Modular_image mod_image_coeff;
            Residue_type_root  root_mod = mod_image_root(a.root());
            if(root_mod != Residue_type_root(0)){
                return Residue_type(mod_image_coeff(a.a0()),
                                  mod_image_coeff(a.a1()),
                                  root_mod);
            }else{
                return Residue_type(mod_image_coeff(a.a0()));
            }
        }
    };

    struct Modular_image_representative{
        NT operator()(const Residue_type& a){
            typename MT_ROOT::Modular_image_representative mod_image_inv_root;
            typename MT_COEFF::Modular_image_representative mod_image_inv_coeff;

            if(a.is_extended()){
                return NT(
                        mod_image_inv_coeff(a.a0()),
                        mod_image_inv_coeff(a.a1()),
                        mod_image_inv_root(a.root()));
            }else{
                return NT(mod_image_inv_coeff(a.a0()));
            }
        }
    };
};

/////////// MODULAR_TRAITS END

} //namespace CGAL

#endif

